We hypothesize that infants with RDS and who respond poorly to surfactant therapy without acute improvement in pulmonary function (studied by tidal volume, compliance and oxygen saturations) or hemodynamics (Doppler-derived cardiac output, blood pressure heart rate) are at greater risk for development of severe BPD, and that this will correlate with low levels of EGF and cortisol. Biostatistician, Informatics ONLY.